Ice fishing has long been a popular past time, and over the years various specialized winter fishing gear has been developed for ice fishing applications. The conventional casting reel and fishing rod normally used by a fisherman in summer months, for example, has gradually been replaced by specialized ice fishing rigs which may be baited and placed over an ice fishing hole cut in the ice cover. Such rigs may be left unattended until a fish takes the bait and triggers a signalling device mounted on the rig. These existing devices are commonly referred to as a "tip-up."
Various prior art tip-up signalling devices have heretofore been developed for use with ice fishing rigs. By far the most common such tip-up mechanism is that of a signal flag, which is mounted on the rig. The flag is automatically triggered into a signalling position in response to a pull upon the fishing line by a fish. The signal flag includes a flag shaft pivotally mounted to the base of the rig at one end and having a flag attached to the opposite free end. Movement of the free end of the shaft into a signalling position is caused by a biasing spring or flexible shaft member, which is triggered by release of a retaining latch responsive to movement of the fishing line. A general discussion of such prior art, for example, may be found in U.S. Pat. No. 4,373,287 to Grahl. Another tip-up mechanism appears in U.S. Pat. No. 3,698,117 to Wiltse, which discloses an ice fishing tip-up including a rotatable reel having fishing line wound thereon and a signal member which is pivotally mounted to the reel in such a manner as to oscillate relative to the ice fishing rig as the fish pulls line off the reel.
Such prior art tip-up devices have not been completely satisfactory. A major disadvantage common to these devices, for example, is that the signalling device is generally exposed to the outside elements of the cold winter climate, and is susceptible of freezing up and becoming inoperative due to the accumulation of snow and ice upon the signalling device. It is further possible for such exposed signalling devices to accidentally release due to wind disturbance.
Another major disadvantage associated with these prior art signalling devices is that they cannot be used in conjunction with conventional fishing rod and casting reel fishing gear. The specialized ice fishing rigs which include these tip-up signalling devices commonly lack the degree of maneuverability and control which a fisherman desires to effectively hook and play a fish which has taken the bait.
Still another disadvantage of these prior art signalling devices is that a relatively strong pull is often required on the fishing line to activate the signalling device. On the signal flag tip-up device, for example, the downward pull exerted by the fish on the fishing line must be sufficient to overcome the resistance of the retaining latch and permit release of the flag shaft. Thus the fisherman does not observe the so-called "nibbling" by the fish prior to the fish actually taking the bait. It is further noted that many of these specialized ice fishing rigs include a fishing line reel presenting additional rotational resistance to any downward movement of the fishing line. Accordingly, many potential fish catches go undetected and the bait may also be lost without one being aware of the presence of a fish. Moreover, attempts to adjustably increase the sensitivity of the signal flag tip-up devices is likely to yield similarly unacceptable results and cause false signals, such as accidental release of the signal flag due to gusts of wind.
Thus, there is a need for an improved signalling device for use in ice fishing which is more sensitive and reliable than the presently available ice fishing rigs and which is further capable of being used with conventional fishing gear to provide the ice fisherman with greater flexibility and control than is offered by the prior art devices.